This invention relates to compositions of liquids employed in display devices wherein the movement of a plurality of mutually immiscible liquids is important in the normal operation of the device. More particularly, it relates to such compositions wherein the number of mutually immiscible liquids is three or more.
Mutually immiscible liquids are those which after intimate mixing with every other liquid phase of the system maintain separate liquid phases at equilibrium. No matter how thoroughly the liquids are mixed, they will always separate into the same number of layers on standing.
A large number of display devices are known which depend on the movement of two mutually immiscible liquids. Generally, the liquids are colored and contained in a transparent container. Examples of such devices can be found in U.S. Pat. Nos. 1,979,336; 2,054,275; 2,162,897; 3,058,245; 3,387,396; 3,564,740; 3,570,156; 3,613,264; 3,629,958; 3,738,036; 3,843,244; 3,973,340; 4,034,493; and 4,057,921, none of which gives an example using more than two mutually immiscible liquids or teaches how such could be achieved.
One example of a system of three liquid layers can be found in U.S. Pat. No. 3,629,958, which describes a composition of diisobutyl adipate, water, and dimethyl phthalate for use in a visual device to simulate wave motion. However, although the top layer is immiscible with the middle one and the bottom layer is immiscible with the middle one, the top layer is not immiscible with the bottom one. Thus this device maintains three layers as long as the top layer never contacts the bottom one, but upon vigorous shaking, only two layers remain.
The only known examples of use in display devices of three or more mutually immiscible liquids are found in U.S. Pat. No. 4,085,533. All the liquid systems described therein, however, suffer from problems of dyeability and compatibility with preferred plastic containers.
All the systems of four or more mutually immiscible liquids described in U.S. Pat. No. 4,085,533 comprise at least one liquid composed primarily of highly fluorinated organic compounds. It is well known that highly fluorinated organic compounds tend to be immiscible with almost everything else, and thus add additional phases to any system to which they are added. Unfortunately, this immiscibility extends to essentially all conventional dyes. Therefore, fluorinated layers cannot be colored with conventional dyes, or by any other inexpensive and satisfactory method. They must remain colorless. No system has heretofore been known of four mutually immiscible liquids each of which can be dyed a color different from that of any of the other three.
All the three-phase systems which do not contain fluorine disclosed in U.S. Pat. No. 4,085,533 attack thermoplastics which are preferred for construction of the devices described below. It would be highly desirable to have a three-phase system which preserves the integrity of the walls in a preferred device and still be dyeable with conventional dyes.
To be suitable for making an inexpensive consumer device such as a child's toy, the liquids should be inexpensive, not toxic, not combustible, easy to dye different colors, and liquid throughout the range of normal room temperatures and pressures. Most inorganic liquids, such as antimony pentachloride and titanium tetrachloride, are toxic and corrosive. Others are liquid only above room temperature. What are needed are room temperature, mutually immiscible liquid systems of water and inexpensive, not toxic, not combustible, readily dyeable organic compounds compatible with optical plastics.
Since satisfactory systems have apparently not been known, many devices, as in U.S. Pat. No. 4,057,921, in order to achieve multiple colors use multiple chambers or compartments wherein the liquid or pair of liquids in each is isolated from that in all the others.
The visual impact and interest generating capacity of mutually immiscible liquid systems within any given compartment goes up sharply as the number of immiscible liquids is increased. A system of three immiscible liquids is for most applications in display devices far superior to only two. Often, in fact, its effects are qualitatively different from those achievable with only two, in the same way that effects from two liquids can be qualitatively different from those from only one.
One object of the present invention is to provide novel compositions of three and of four mutually immiscible liquids suitable for use in consumer items, especially toys.
Another object is to make possible improved visual display devices.
Another object is to provide liquid mixtures capable of producing color patterns and movements beyond the capability of known mixtures.
Another object is to provide compositions which will make possible novel art forms and toys.
A further object is to provide multi-phase liquid systems which are inexpensive, not toxic, not combustible, not corrosive to plastic, and easy to dye different colors.
Other objects and advantages of the invention will be apparent from the following description.